(CNN) -- A dark comedy cum thriller that swings between manic and straightforward with the occasional dreamy, explanatory romantic flashback, "The Perfect Host" is a mixed bag that veers from inspired lunacy with deft thriller touches to over-the-top madness and occasionally lazy writing.

That's not to say there isn't plenty to enjoy about the film, not the least of which being David Hyde Pierce's performance as Warwick, the host with the most ... reasons to see a shrink.

"The Perfect Host" fits into the category of dark comedy thriller, at least for most of the film. It's a small subset, a mix of genres and a risk by any filmmaker. The box office charts are littered with failed experiments, and it's unlikely that first-time feature director Nick Tomnay (who co-wrote the screenplay with Krishna Jones) has enough here to avoid that fate. Netflix, video on demand and cable viewing seem more natural fits.

First the good: "The Perfect Host" has more twists and turns than a mountain road with at least a few that you might not see coming. The problem with this genre, however, is that it's not so easy to talk about it without revealing some of the things that lurk around the corners.

Pierce is, as usual, a joy to watch. Starting out as an only slightly less prissy version of Niles from TV's "Frasier," Pierce's "Warwick" is a single, well-off aesthete of indeterminate profession who is preparing to host a dinner party when John, a man we know to be an injured bank robber, rings his doorbell. Pretending to be a friend of Warwick's friend Julia (info gleaned from a postcard stolen from Warwick's mailbox), John talks his way into the house, making up his story and plan on the fly.

John isn't very good at that, and in short order, he's blown his "cover" and begins to verbally and physically abuse Warwick, all with a staggering limp and a profusely bleeding cut on his foot. He also vacillates from one extreme to another, at first telling Warwick, "I'm going to kill you. That's a decision I've already made," and in the next sentence telling him that if he behaves himself, he won't get hurt. Well? Which one is it? Menacing evil or just a bad guy having a bad day?

The thing is, the stress of the day, the blood loss, the wine and perhaps something in the wine combine to literally knock John on his ass, providing Warwick with the opportunity to unleash the first in a torrent of bon mots referring to the wine: "It's a cheeky little drop, isn't it?"

From there, the evening (and alas, the film) begins to spin in directions unknown, both comic and horrific, as Pierce moves from effete and scared hostage ("You can't kill me. I'm having a dinner party") to displaying a dazzling array of psychoses that would give any actor a run for his money (not to mention put any real human being in a psych ward).

By the last 20 to 25 minutes, all of the humor and all of the terror have vanished, and what's left is a heist film with a few false endings, a rather needless subplot and a lunatic lead character who is playing it straight. Alas, it seems like the filmmakers couldn't fully commit to funny, suspenseful or horrific and tried to be all three with only middling success. It's almost like they were afraid to pull the trigger and ended up being too cautious.

As for the casting, while Clayne Crawford (a dead ringer for a young Ray Liotta) does a decent job as John, Pierce is basically forced to carry the film, and no actor can fully inhabit as many psychoses in as many genres as he is asked to. Supporting roles are either wooden or nonexistent, and the film would have benefited with more fleshed-out support.

The main problem is that "The Perfect Host" doesn't seem to want to know what it is, and changing genres mid-film is very tricky business.

While it has some truly funny moments and some truly gasp-inducing ones, it's never a really subversive dark comedy and never fully embraces the potential for terror. Basically, the film lets itself off the hook, which is a shame because there's two-thirds of a very good and very twisted film here.